next try, this sh*** lib drives me crazy
diff --git a/src/emuvim/test/unittests/test_sonata_dummy_gatekeeper.py b/src/emuvim/test/unittests/test_sonata_dummy_gatekeeper.py
index 375087d..cbf9c8b 100755
--- a/src/emuvim/test/unittests/test_sonata_dummy_gatekeeper.py
+++ b/src/emuvim/test/unittests/test_sonata_dummy_gatekeeper.py
@@ -37,7 +37,7 @@
 
         # instantiate service
         service_uuid = json.loads(r.text).get("service_uuid")
-        r2 = requests.post("http://127.0.0.1:5000/instantiations", json={"service_uuid": service_uuid})
+        r2 = requests.post("http://127.0.0.1:5000/instantiations", data=json.dumps({"service_uuid": service_uuid}))
         self.assertEqual(r2.status_code, 200)
 
         # give the emulator some time to instantiate everything